1. Field of the Invention
The present invention relates to a system of establishing voice communications using a telephone during data communications.
2. Description of the Related Art
Recently, users are provided with various communications services after outstanding development of communications technology. Data communication is one of these communications services. In the data communication, a home page of a WWW (World Wide Web) can be seen through a browser using a data communications adapter from a wireless telephone terminal such as a PHS (personal handy-phone system), a PDC (personal digital cellular phone), etc. connected to the Internet through a dial-up connection.
There is a system for satisfying a request from a user to immediately make a phone call according to the information (for example, the telephone number of a shop found during the browsing through Web) obtained during the data communication. A Web server calls up the shop through the CGI (common gateway interface) and connects the user terminal to the shop so that the user can directly communicate with the shop through the phone.
FIG. 1 shows the outline of the conventional communications network system for realizing the function of setting voice communications during data communications.
A server 2100 comprises a switching unit 2105 and is connected to a telephone network 2110 through a switching unit 2105. A personal computer 2101 is connected to the telephone network 2110 through a modem 2108 containing a telephone 2107 and an NCU (network control unit). A telephone 2106 is also connected to the telephone network 2110 through the switching unit 2105 of the server 2100.
A Web server 2102 is implemented in the server 2100, and the Web server 2102 is connected to the switching unit 2105 through a CGI program 2103 or an NCU built-in modem 2104 so that data can be transmitted to the telephone network 2110. A Web browser 2109 is installed in the personal computer 2101, and accesses a home page, etc. provided by the Web server 2102 implemented in the server 2100 through the NCU built-in modem 2108.
In FIG. 1, the line through which the personal computer 2101 accesses the server 2100 is provided separately from the line of the telephone 2107 of the user of the personal computer 2101. The user of the personal computer 2101 sees the home page of the server 2100 on the Web browser 2109. When the user orders goods, the user checks the telephone number of the shop stored on the home page and clicks the mouse button, etc. with the telephone number on the home page pointed to. Thus, the Web server 2102 instructs the CGI program 2103 to call up the user's telephone 2107 and the telephone 2106 of the shop through the switching unit 2105 to connect the user's telephone 2107 to the telephone 2106 and allow the user to communicate with the shop and place an order.
This method is effective if the user has a telephone line separate from the data communications line as shown by the example in FIG. 1. However, the method is not effective when the user uses the same line as a telephone and data communications line. For example, when a personal computer is connected to a portable telephone in a line switching system through a data communications adapter, data communications and voice communications cannot be simultaneously established.
That is, in a line switching network or a packet switching network in which a voice packet cannot be simultaneously processed with a data packet, the line is occupied by the data communications, and no telephone calls can be issued or received.
To make a telephone call, the data communications should be terminated to disconnect the line. In this case, when the data communications are resumed, it is necessary to start the data communications from the very beginning. This is inconvenient to the user.
For example, when a user sees home pages on the Web server and traces various links, the user has to terminate the Web browser and the data communications to disconnect the line before making a telephone call. When the user terminates the telephone call, a line connection should be made to re-establish data communications with the Web server, the Web browser should be set, the Web server should be accessed, and the link should be traced again from the first home page.